Nuke It

A mid the bright lights and glitz of America's gambling mecca, a small research company has applied for a patent that may revolutionize how you harvest grain.

Titled “Method and Apparatus For Drying Harvested Crops Prior To Storage,” the 33-page patent application details how to use excess combine engine heat and microwave technology to dry grain, on-the-go, while harvesting.

Sound like snake oil? Meet Alvin Snaper, the wizard behind the Las Vegas, NV-based research and development company who's applied for the patent.

Snaper, the 72-year-old vice president and director of Power Technology, Inc., and the inventor of the well-known orange drink Tang, makes no bones about the invention called Mikro Dri Technology — it works.

The prototype system takes excess engine heat and uses fluidic air movement and magnetrons from 12 microwave ovens to dry corn 10-11 moisture points in a simulated, real-time combining scenario, all at 25 bu/minute.

While Snaper admits many things can be done in a laboratory situation, he's aware they can often be difficult to translate to real-life industry.

“We've always looked at how practical, reliable and cost effective the end product will be,” he notes. “Our goal was to design a cost-effective, reliable system that could be installed on a combine to dry grain.”

The prototype is about 18” deep, 4' wide and 6' high. The grain, preheated with excess engine heat, enters the chamber at the top and falls, being dried as it passes through the microwaves. As it exits the chamber, with the fluidic air movement components carrying the grain, excess moisture removal and further drying continues as it moves to the grain tank.

But is it feasible in the eyes of engineers closer to agriculture? Dirk Maier, ag engineer at Purdue University, is skeptical. “If someone invents a new mousetrap, it's better and you can prove the claims, that would be great,” he says. “But I'm always a little hesitant because I've been around this for so long.”

Maier has spent the majority of his research career looking at post-harvest engineering and value-added processing concepts. At first brush, he says the rate of drying and the amount of moisture being removed is what raises his eyebrow.

Whether it's propane-dried corn or microwave/excess heat-dried corn, Maier says the issue comes down to the energy needed to heat the corn and the air movement to carry the moisture away.

McGill University in Montreal conducted studies in the early 1990s on power requirements for drying corn. Maier says their outcomes showed 0.5 watts of power needed for every wet gram of corn to be dried. At the rate of 25 bu/minute, that would translate to 65 million btu's per hour. That's equivalent to an energy input of over 25,000 hp, for the microwave drying, airflow-assisted process.

To carry 10 points of moisture away at 25 bu of drying per minute, it also translates to 9,882 lbs of water removed from corn in an hour of combine operation.

Under ideal conditions, that would require 290,000 cu ft of air, or about three times higher than a typical 1,500-bu on-farm dryer, to achieve the desired result.

While Maier admits that there may be information in the unavailable claims portion of the patent application that could refute some of his calculations, he doubts the system will work. “Those are some pretty huge numbers,” he notes. “It is a bit staggering to expect to accomplish this while driving a combine through the field.”

While microwave drying has been extensively researched and used in the food industry, Maier says the difficulty in agriculture has been the mass amounts of grain that need to be dried at one time. “If you have thick layers of bulk grain, microwaves cannot penetrate kernels to initiate the drying.”

Snaper stands by his patent claims, however, mostly because of the common sense approach they used in testing. Initially, they moved the corn on a belt through a small microwave chamber as it dried. This allowed them to assess the drying process and ensure there was no damage to the corn.

They then determined the power and microwave requirements. “We literally went out and bought a dozen microwave ovens and used the necessary parts,” he says.

As they built the prototype, the research team decided to add excess engine heat to the concept. Senior Engineer Chuck Warn says that was the key to making the microwave project work. “The fact that there is so much excess engine heat, around 1 million btu's generated per hour, lead us to believe we could maximize that energy and gain efficiencies in the drying process,” he says.

Through prototype testing, Snaper says: “We needed to know if it could be done at high enough speeds and volume, with minimum power, to be practical. And it was,” he says. “If you need Hoover Dam to power it, it's not practical.”

Both Snaper and Warn estimate that a commercialized unit would be about the same size as the prototype. It's designed to be either retrofitted on an existing combine or as an addition to a new combine.

Kansas State Economist Terry Kastens shares skepticism similar to Maier, noting that continuously vaporizing a stream of water equivalent to two or three garden hoses is hard to imagine. But the upside potential is exciting. “If it works and becomes commercialized, it would change the convenience and efficiency of harvesting,” he notes.

And the benefits would go beyond corn for Kastens. “I can see it being as important for wheat as corn,” he says. “With wheat, moisture varies a great deal at harvest, which dictates when you can harvest. That would dramatically change with this type of system.”

While not on a fast track, the Mikro Dri project took about 2 ½ years to go from concept, research, design and testing to patent application. The research has been funded by a private, undisclosed group of investors, many of whom are engaged in Midwest farming.

The next phase of development will be the “sweat engineering,” which involves taking the prototype and fitting it onto a combine. Snaper says the investment group is working on securing additional funding to move ahead with that final stage of the research.

Snaper applied for the patent in September 2001. While the U.S. Patent office can be unpredictable, he gives a ballpark estimate of 18-24 months from application to patent approval. But he's confident: “I've never lost a patent yet.”

The Snaper Profile

Inventor Alvin Snaper, vice president and director of Power Technology, Inc., has over 600 patents credited to his name.

Besides Tang, the list includes the NASA Apollo Astronaut's Photo Pack, the IBM Selectric typewriter ball and a line of industrial hard coatings currently being used by companies such as Gillette, Boeing and TRW.

He is the only person to receive the “Best Patent of the Year” award on three separate occasions by a leading design engineering magazine.